It underlines the role of extensional tectonics during sedimentation. Recently released industry seismic data image a 6 km thick dinantian succession in the stainmore basin, and are used to interpret deposition in response to extensional subsidence. An animated tectonic reconstruction of southwestern north. Sharma government postgraduate college, sirohi rajasthan 307001 india email. Extensional tectonic environment a region of the earths crust or lithosphere that is spreading apart due to tectonic forces acting on the surrounding areas. The basin is bounded to the north by the lunedalewigglesworthbutterknowle en echelon suite of normal faults. Recent extensional tectonics on the moon revealed by the. Kt magmatism and basin tectonism in western rajasthan. This type of tectonics is found at divergent plate boundaries, in continental rifts, during and after a period of continental collision caused by the lateral spreading of the thickened crust formed.
Rifts are regions in which extensional tectonics i. Kt magmatism and basin tectonism in western rajasthan, india, results from extensional tectonics and not from reunion plume activity kamal k. The title extensional tectonics of centralnorthern mexico reflects a fraction of studies on mexican country, which are summed up in a research sponsored by the ministry of education and the national council for science and technology and identified with number 167638. The identification of early cretaceous, riftoblique extension that predated the main rifting event in the barmer basin. The shape of this curve is a result of extensional tectonics, and gradient changes record vari. The remaining por tions of the orogenic wedge are dominated by rocks of the jotun nappe, which is a major fragment of mostly crystal line proterozoic crust that appears to have been thrust for more than 300 km e. Pdf extensional tectonics, graben development paper. It is proposed that each episode was controlled by a reactivation of a fracture system in the precambrian basement. Extensional tectonics in the vicinity of a transform fault in. Extensional tectonics in the caledonides of southern. Sedimentary models for extensional tiltblockhalfgraben basins. Extensional tectonics wikipedia republished wiki 2. Recent extensional tectonics on the moon revealed by the lunar reconnaissance orbiter camera. Geological society, london, special publications geometry and.
A systematic comparison of experimental setups for. View extensional tectonics research papers on academia. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses. At the junction between an oceanic transform fault and the adjacent ridge segments, there is normally a curved fabric. Extensional tectonics and stratigraphy of the north atlantic margins authors a. As the surface of the earth is stress free, the component of simple shear must be transmitted from below and implies a displacement of the crust relative to the mantle. Extensional tectonics is associated with the stretching and thinning of the crust or the lithosphere. Previously unrecognised extensional tectonics exposed in. The types of structure and the geometries formed depend on the amount of stretching involved. Modes of extensional tectonics brian wernicke and b. Regional tectonics are extensional and there is little structural evidence for earlier crustal thickening. Abstract this paper discusses the geological and geophysical interpretation of rift structures in the region extending from the rio grande rise, in the southeastern brazilian margin, towards the cabo frio high, which separates the campos and santos basins. The fact that lowangle normal faults exist in both extensional and compressional tectonic settings, and can actively slip at low angles extensional tectonics workshop course summary extensional structures provide some of the worlds largest known oil reservoirs and remain one of the major frontier plays of the immediate future, both onshore and, particularly, in deep water offshore. Tectonics presents original research articles that describe and explain the evolution, structure, and deformation of earths lithosphere including across the range of geologic time.
The menderes massif in western anatolia was exhumed initially as an asymmetric core complex in the early miocene due to extension beginning in the oligocene and then the central. Backarc basins are regions of extension behind subduction zones and are often locations where volcanoes form. Another widespread setting for extensional tectonics are upper plates above subduction zones subjected to. Burchfiel department of earth and planetary sciences, massachussetts institute of technology, cambridge, ma 029, u. Faulting and faultrelated processes key issues in earth sciences on free shipping on qualified orders. Received 1 september 1981, accepted in revised form 10 march 1982. Basin and range extensional tectonics at the latitude of las vegas, nevada brian wernicke.
The relationship of extensional and compressional tectonics. Find materials for this course in the pages linked along the left. Extensional tectonics and collapse structures in the suez rift egypt. Aulacogens may represent failed arms of threearmed rifts, or they may simply be older rifts formed long before the development of the continental margin, during an earlier episode of rifting at a different. An animated tectonic reconstruction of southwestern north america since 36 ma nadine mcquarrie brian p. The majority of the chapter is devoted to a discussion of stretching processes that affect the whole lithosphere and are driven by the relative motion of lithospheric plates. Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere. We attempt, by means of quantitative theoretical analysis guided by real geological examples, to establish some ground rules for interpreting extensional phenomena. Extensional tectonics an overview sciencedirect topics. Front matter continental tectonics the national academies.
Rifting the process by which continental lithosphere undergoes extensional deformation stretching by the formation and activity of normal faults. Unfortunately, this book cant be printed from the openbook. The lithosphere lithosphere is comprised of the upper mantle and the crust, the outer shell of the earth. Extensional tectonics in the himalayan orogen, zanskar, nw india. Pdf extensional tectonics in the himalayan orogen, zanskar. Lecture notes structural geology earth, atmospheric.
Aulacogen an unsuccessful rift that cuts across a continental margin at a high angle to the margin. Arundian synrift sequence more than 4 km thick includes footwallderived. This first episode of extension left the cms with the normal ocotillo canyon fault and a related graben containing nonmarine syn extensional sediments lower part of the split mountain group. Pdf on oct 11, 2015, jesus galindozaldivar and others published extensional tectonics, graben development paper find, read and cite all the research you need on researchgate. The earth is composed of layers of different composition and physical properties, principally the solid central core, the fluid peripheral core, the viscous mantle, and the solid. In terms of plate tectonics, extension systems are associated with. Tectonics, in situ stress stress, faults and rock failure. Extensional crustal tectonics and crustmantle coupling, a. Ashton embry, benoit beauchamp, in the sedimentary basins of the united states and canada second edition, 2019. A curve with a negative gradient results, and the intercept of the curve with the ordinate defines the null point. Public domain topics comparison, computer programs, free flow, mach number, separated flow, subsonic flow, three dimensional flow, convergentdivergent nozzles, experiment design, predictions, pressure gradients, propulsion system configurations. Extensional tectonics and salt structures, maribshabwa. Box 1047, blindern, n0316 oslo, norway received 24 october 1995. Extensional tectonics in the caledonides hardangerfjord shear zone figure 2.
The sverdrup basin originated due to an episode of extensional tectonics that affected much of the caledonianellesmerian orogenic belt in early. Proprietary seismicreflection profiles show a system of downtotheeast precambrian extensional faults. There are still many important questions of extensional tectonics. Extensional tectonism may form during as well as after the contractional history of a collisional orogeny. Extensional tectonics wikimili, the free encyclopedia. Article pdf available in geological society london special publications 741. The trollaskagi peninsula is located just south of the junction between the kolbeinsey ridge and the tjornes fracture zone and offers a rare opportunity for studying the three.
The chosen examples all have in common a distributed extensional deformation and a high heat flow, thus a weak crust and thin lithosphere. The central and southern appalachians have a long history of interrelated extensional and compressional tectonics. Basins that form within an extensional tectonic setting are characterized by the development of depressions, bounded by normal faults, within. The tectonics of the fault zone on south uist are dominated by structures associated with several episodes of pervasive topdowntothese to ene brittle extensional deformation, which are progressively overprinted by protophyllonitic and phyllonitic fabrics associated with topdowntothee to ene extension. Extensional tectonics is concerned with the structures formed by, and the tectonic processes. Typically, aulacogens transect the grain of an orogen that borders the margin. Study of the structures formed by, and the processes associated with, the stretching of a planetary bodys crust. Extensional tectonics of the outer hebrides fault zone, south. Several episodes of granite magmatism are recorded, culminating in the late. We have analysed potential field data gravity and magnetic from the argentine to the brazilian oceanic basins and extending over the.
Abstract we investigate the feedbacks between surface processes and tectonics in an extensional setting by coupling a 2. Wernicke division of geological and planetary sciences, ms 10023, california institute of technology, pasadena, ca 91125 abstract we present tectonic reconstructions and an. The course covers the field level all the way up to basinscale architecture, and the role of salt and strikeslip tectonics in the development of extensional basins. Sometime after the first and before the start of the second episode of. Compressional metamorphic core complexes, lowangle normal. Divergent extensional tectonic regimes springerlink. On the moon, extensional tectonic features have only been observed close to the influence of the mare basaltfilled basins and floorfractured craters. Apr 01, 2000 read extensional tectonics in the caledonides. Extensional tectonics fall 2005 1 the jargon of extensional tectonics for the following terms, draw a simple illustrative diagram consisting of either a map and crosssection or a block diagram.
Peloponnesus in the southwestern part of the aegean is formed by a heterogeneous pile of alpine thrust sheets that was reworked by normal faulting from upper miocene to recent times. Longer aftershocks duration in extensional tectonic. Download and read free online basin and range extensional tectonics near the latitude of las vegas, nevada memoir geological society of america by brian p. Modes of extensional faulting controlled by surface processes.
Dec 08, 2011 this file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. The aegean region western anatolia, aegean sea and greece is one of the areas of the earth under the effect of extensional tectonics and includes the typical features of core complexes in this type of region. Extensional tectonics, a slab window and the arrival of. Andersen institutt for geologi, universitetet i oslo, p. Compressional and extensional tectonics in lowmedium pressure granulites from the larsemann hills, east antarctica volume 2 issue 2 c. Pdf continental extensional tectonics researchgate. Pdf on jun 1, 2010, ibrahim cemen and others published extensional tectonics in the basin and range, the aegean, and western anatolia. Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere deformation styles. Compressional and extensional tectonics in lowmedium. Although hundreds of papers have been devoted to the geometric and kinematic analysis of compressional tectonic regimes, surprisingly little has been written about the details of largescale strain in extended areas. Since middle pliocene, the axial part of this foldthrust belt underwent an extensional tectonics.
Basin and range extensional tectonics at the latitude of. Strikeslip faulting is a common mode of deformation in both continental and oceanic crust and. Lecture notes structural geology earth, atmospheric, and. Rifting, seafloor spreading, and extensional tectonics geokniga. Extensional tectonics and sedimentation, eastern gulf of. Geological and geophysical interpretation of the rio. The model predicts significant extensional deformation in regions with surface heat flow 65 mwm 2 subjected to a tensile tectonic force of 3. Extensional tectonic regimes are therefore primarily associated with divergent i. Extensional tectonic regimes are primarily associated with divergent plate boundaries, but can also commonly be found in plate interiors in the form of localized rift zones and extensional basins.
Pdf extensional tectonics in the basin and range, the aegean. If you need to print pages from this book, we recommend downloading it as a pdf. Pdf extensional tectonics in mt parnon peloponnesus. Drilling through an extensional normal fault encounters a stratigraphic gap. Predictive permeability model of extensional faults in crystalline. Structural geology, tectonics and geodynamics form a coherent and interdependent.
Dec 22, 2019 extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere. Tension fractures and extensional tectonics nature. This type of tectonics is found at divergent plate boundaries, in continental rifts, during and after a period of continental collision caused by the lateral spreading of the thickened crust formed, at releasing bends in strikeslip faults, in backarc basins, and on the continental end of. The structural and sedimentological evolution of a 100 km. Extensional tectonics and stratigraphy of the north. Extensional definition and meaning collins english. Analysis of structural traps in extensional settings.
Late to postvariscan extensional tectonics in south cornwall. Any synorogenic extensional deformation must have occurred prior to the onset of this extensional history, which is dated to circa 405 ma. Extensional tectonics is concerned with the structures formed, and the tectonic processes associated with, the stretching of the crust or lithosphere. Granite magmatism and extensional tectonics in southern. Extensional tectonics in the caledonides of southern norway, an overview torgeir b. Geological society, london, special publications geometry.
Faults which postdate variscan contractional deformation are ubiquitous in south cornwall. Upper miocenelower pliocene extension in mt parnon was. Sedimentary models for extensional service email alerting new articles cite this article click here to receive free email alerts when request permission part of this article click here to seek permission to reuse all or subscribe collection london, special publications or the lyell click here to subscribe to geological society, notes. Longer aftershocks duration in extensional tectonic settings.
Extensional tectonics free online course materials. A characteristic pattern of normal faults that we have studied in several regions illustrates successive geometries relating to increasing amounts. Rotational normal fault a normal fault whose hanging wall block rotates around a horizontal axis during slip. Three broad geometrickinematic types can be defined. Your chance to have a onetoone lesson with bestselling language expert paul noble, try a free audio sample of his brand new mandarin chinese course. Lecture notes section contains class notes for the topic covered in the lectures. Subsidence the sinking of the surface of the lithosphere. Hancock and others published continental extensional tectonics find, read and cite all the research you need on researchgate. Normal faults form in divergent plate boundaries, areas of gravitational collapse and extension above salt domes. Wikipedia definition extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere. The eastern margin of the gulf of suez displays spectacular interrelationships between riftborder fault systems and sedimentation patterns. Rifting, seafloor spreading, and extensional tectonics.